1. Subject : IoT& wireless sensor Network Code : 17EC752 DEPT. OF ECE, SJBIT 1

2. Text Books: Raj Kamal, ”Internet of Things-Architecture and design principles”, McGraw Hill Education. Holger Karl & Andreas Willig, "Protocols And Architectures for Wireless Sensor Networks", John Wiley, 2005. Feng Zhao & Leonidas J. Guibas, “Wireless Sensor Networks- An Information Processing Approach", Elsevier, 2007. Reference Books: Kazem Sohraby, Daniel Minoli, & Taieb Znati, “Wireless Sensor Networks- Technology, Protocols, And Applications”, John Wiley, 2007. Anna Hac, “Wireless Sensor Network Designs”, John Wiley, 2003. DEPT. OF ECE, SJBIT 2

3. Syllabus MODULE-1 Overview of Internet of Things: IoT Conceptual Framework, IoT Architectural View, Technology Behind IoT, Sources of IoT,M2M communication, Examples of IoT. Modified OSI Model for the IoT/M2M Systems, data enrichment, data consolidation and device management at IoT/M2M Gateway, web communication protocols used by connected IoT/M2M devices, Message communication protocols (CoAP-SMS, CoAP- MQ, MQTT,XMPP) for IoT/M2M devices. DEPT. OF ECE, SJBIT 3

4. INTERNET OF THINGS: AN OVERVIEW DEPT. OF ECE, SJBIT 4

5. IoT Definition “Internet of Things means a network of physical things (objects) sending, receiving, or communicating information using the Internet or other communication technologies and network just as the computers, tablets and mobiles do, and thus enabling the monitoring, coordinating or controlling process across the Internet or another data network.” DEPT. OF ECE, SJBIT 5

6. IoT Vision Internet of Things is a vision where things (wearable watches, alarm clocks, home devices, surrounding objects) become ‘smart' and function like living entities by sensing, computing and communicating through embedded devices which interact with remote objects (servers, clouds, applications, services and processes) or persons through the Internet or Near- Field Communication (NFC) etc. DEPT. OF ECE, SJBIT 6

7. Use of Internet of Things concept for streetlights in a city DEPT. OF ECE, SJBIT 7

8. Smart and Hyper connected Devices Hyper connectivity means use of multiple systems and devices to remain constantly connected to social networks and streams of information. Smart devices are devices with computing and communication capabilities that can constantly connect to networks. DEPT. OF ECE, SJBIT 8

9. A general framework for IoT using smart and hyper connected devices, edge computing and applications DEPT. OF ECE, SJBIT 9

10. IoT CONCEPTUAL FRAMEWORK A single object (umbrella) communicating with a central server for acquiring data. The following equation describes a simple conceptual framework of IoT Physical Object + Controller, Sensor and Actuators + Internet = Internet of Things DEPT. OF ECE, SJBIT 10

11. Conceptually represents the actions and communication of data at successive levels in IoT consisting of internetworked devices and objects. Gather + Enrich + Stream + Manage + Acquire + Organise and Analyze = Internet of Things with connectivity to data centre, enterprise or cloud server DEPT. OF ECE, SJBIT 11

12. Oracle's IoT architecture DEPT. OF ECE, SJBIT 12

13. Another equation which conceptualizes the general framework for IoT using the cloud based services is Gather + Consolidate + Connect + Collect + Assemble + Manage and Analyze = Internet of Things DEPT. OF ECE, SJBIT 13

14. IBM IoT conceptual framework DEPT. OF ECE, SJBIT 14

15. IoT ARCHITECTURAL VIEW DEPT. OF ECE, SJBIT 15

16. TECHNOLOGY BEHIND IoT Hardware (Arduino Raspberry Pi, Intel Galileo, Intel Edison, ARM mBed, Bosch XDK110, Beagle Bone Black and Wireless SoC) Integrated Development Environment (IDE) for developing device software, firmware and APIs Protocols [RPL, CoAP, RESTful HTTP, MQTT, XMPP (Extensible Messaging and Presence Protocol)] DEPT. OF ECE, SJBIT 16

17. Communication (Powerline Ethernet, RFID, NFC, 6LowPAN, UWB, ZigBee, Bluetooth, WiFi, WiMax, 2G/3G/4G) Network backbone (IPv4, IPv6, UDP and 6LowPAN) Software (RIoT OS, Contiki OS, Thing square Mist firmware, Eclipse IoT) Internetwork Cloud Platforms/Data Centre (Sense, ThingWorx, Nimbits, Xively, openHAB, AWS IoT, IBM BlueMix, CISCO IoT, IOx and Fog, EvryThng, Azure, TCS CUP) DEPT. OF ECE, SJBIT 17

18. The following five entities can be considered for the five levels behind an IoT system 1. Device platform 2. Connecting and networking 3. Server and web programming 4. Cloud platform enabling storage 5. Online transactions processing DEPT. OF ECE, SJBIT 18

19. Server-end Technology IoT servers are application servers, enterprise servers, cloud servers, data centres and databases. Servers offer the following software components: Online platforms Devices identification, identity management and their access management Data accruing, aggregation, integration, organising and analyzing Use of web applications, services and business processes DEPT. OF ECE, SJBIT 19

20. Major Components of IoT System 1.Physical object 2.Hardware 3.Communication module 4.Software DEPT. OF ECE, SJBIT 20

21. Sensors and Control Units Sensors Control Units DEPT. OF ECE, SJBIT 21

22. Communication Module Software Middleware Operating Systems (OS) DEPT. OF ECE, SJBIT 22

23. IoT software components for device hardware DEPT. OF ECE, SJBIT 23

24. SOURCES OF IoT Popular IoT Development Boards Arduino Yún Microduino Intel Galileo Intel Edison Beagle Board Raspberry Pi Wireless Inventors Kit (RasWIK) DEPT. OF ECE, SJBIT 24

25. Wireless Sensor Networks (WSNs) WSN Definition Wireless Sensor Network (WSN) is defined as a network in which each sensor node connects wirelessly and has capabilities of computations for data compaction, aggregation and analysis plus communication and networking. WSN node is autonomous. DEPT. OF ECE, SJBIT 25

26. M2M COMMUNICATION Machine-to-machine (M2M) refers to the process of communication of a physical object or device at machine with others of the same type, mostly for monitoring but also for control purposes. DEPT. OF ECE, SJBIT 26

27. The close difference between M2M and IoT is that M2M must deploy device to device, and carry out the coordination, monitoring, controlling of the devices and communicate without the usage of Internet. whereas IoT deploys the internet, server, internet protocols and server or cloud end applications, services or processes. DEPT. OF ECE, SJBIT 27

28. M2M Architecture It consists of three domains 1. M2M device domain 2. M2M network domain 3. M2M application domain DEPT. OF ECE, SJBIT 28

29. Three domains of M2M architecture DEPT. OF ECE, SJBIT 29

30. M2M device communication domain consists of three entities: physical devices, communication interface and gateway. Communication interface is a port or a subsystem, which receives the input from one end and sends the data received to another. M2M network domain consists of M2M server, device identity management, data analytics and data and device management similar to IoT architecture (connect + collect + assemble + analyse) level. M2M application domain consists of application for services, monitoring, analysis and controlling of devices networks. DEPT. OF ECE, SJBIT 30

31. Software and Development Tools Examples of M2M software and development tools are as follows: Mango is an open source M2M web-based software. It supports multiple platforms, multiple protocols, databases, meta points, user-defined events and import/export. 20 20 DEPT. OF ECE, SJBIT 31

32. Mainspring from M2MLabs is a development tool, and source framework for developing M2M applications. It enables Flexible modeling of devices and their configurations Communication between devices and applications Validation and normalization of data Long-term data storage and data retrieval functions Programming in Java and Apache Cassandra Usages of no SQL database. DEPT. OF ECE, SJBIT 32

33. Device Hive is an M2M communication framework. It is an M2M platform and integration tool. It enables connecting devices to the IoT. It includes web-based management software that creates security-rules-based e-networks and monitoring devices. Open M2M Protocols, Tools and Frameworks: Following are the open protocols, tools and frameworks for M2M: XMPP, MQTT-OASIS standards group and OMA LWM2M-OMA standard group for protocol DEPT. OF ECE, SJBIT 33

34. EXAMPLES OF IoT Wearable Smart Watch DEPT. OF ECE, SJBIT 34

35. DEPT. OF ECE, SJBIT 35

36. Smart Home A connected home has the following applications deployed in a smart home: Mobile, tablets, IP-TV, VOIP telephony, video-conferencing, video-on- demand, video-surveillance, Wi-Fi and internet Home security: Access control and security alerts Lighting control Home healthcare Fire detection or Leak detection Energy efficiency Solar panel monitoring and control Temperature monitoring and HVAC control Refrigerator network with maintenance and service centers DEPT. OF ECE, SJBIT 36

37. DEPT. OF ECE, SJBIT 37

38. Smart Cities 1. Layer 1 consists of sensors, sensor networks and devices network in parking spaces, hospitals, streets, vehicles, banks, water supply, roads, bridges and railroads. Bluetooth, ZigBee, NFC, WiFi are the protocols used at this layer. 2. Layer 2 captures data at distributed computing points where data is processed, stored and analyzed. 3. Layer 3 is meant for central collection services, connected data centers, cloud and enterprise servers for data analytics applications. DEPT. OF ECE, SJBIT 38

39. Four-layer architectural framework developed at CISCO for a city DEPT. OF ECE, SJBIT 39

40. Modified OSI Model for the IoT/M2M Systems DEPT. OF ECE, SJBIT 40

41. DEPT. OF ECE, SJBIT 41

42. Figure shows a similarity with the conceptual framework in Equation Gather + Enrich + Stream + (Manage + Acquire + Organise +Analyze) = IoT Applications and Services DEPT. OF ECE, SJBIT 42

43. Problem What are the architectural layers in a modified OSI model for Internet of smart streetlights application in Example 1.1 Solution Consider a model for Internet of streetlights, Following are the layers for data interchange in the modified OSI model: DEPT. OF ECE, SJBIT 43

44. DEPT. OF ECE, SJBIT 44

45. L1: It consists of smart sensing and data-link circuits with each streetlight transferring the sensed data to L2. L2: It consists of a group-controller which receives data of each group through Bluetooth or ZigBee, aggregates and compacts the data for communication to the Internet, and controls the group streetlights as per the program commands from a central station. L3: It communicates a network stream on the Internet to the next layer. DEPT. OF ECE, SJBIT 45

46. L4: The transport layer does device identity management, identity registry and data routing to the next layer L5: The application-support layer does data managing, acquiring, organising and analyzing, and functionalities of standard protocols such as CoAP, UDP and IP. L6: The application layer enables remote programming and issue of central station directions to switch on-off and commands of services to the controllers along with monitoring each group of streetlights in the whole city. DEPT. OF ECE, SJBIT 46

47. ITU-T Reference Model DEPT. OF ECE, SJBIT 47

48. Lowest layer, L1, is the device layer and has device and gateway capabilities. Next layer, L2, has transport and network capabilities. Next layer, L3, is the services and application-support layer. The support layer has two types of capabilities—generic and specific service or application-support capabilities. Top layer, L4, is for applications and services. DEPT. OF ECE, SJBIT 48

49. COMMUNICATION TECHNOLOGIES Physical cum data-link layer in the model consists of a local area network(LAN) / personal area network(PAN). A local network of IoT or M2M device deploys one of the two types of technologies— wireless or wired communication technologies. Figure shows connected devices (1 st to i th ) connectivity using different technologies for communication of data from and to devices to the local network connectivity to a gateway. DEPT. OF ECE, SJBIT 49

50. Connected devices 1 st to i th connected to the local network and gateway using the WPAN or LPWAN network protocols DEPT. OF ECE, SJBIT 50

51. The figure shows the local area network of devices. The connectivity between the devices (left-hand side) is by using RF, Bluetooth Smart Energy, ZigBee IP, ZigBee NAN (neighbourhood area network), NFC or 6LoWPAN or mobile. Tens of bytes communicate at an instance between the device and local devices network. DEPT. OF ECE, SJBIT 51

52. Wireless Communication Technology Near-Field Communication NFC is a short distance (20 cm) wireless communication technology. It enables data exchange between cards in proximity and other devices. Examples of applications of NFC are proximity-card reader/RFID/IoT/M2M/mobile device, mobile payment wallet, Electronic keys for car, house, office entry keys and biometric passport readers. DEPT. OF ECE, SJBIT 52

53. RFID Radio Frequency Identification (RFID) is an automatic identification method. RFIDs use the Internet. RFID usage is, therefore, in remote storage and retrieval of data is done at the RFID tags. An RFID device functions as a tag or label, which may be placed on an object. The object can then be tracked for the movements. The object may be a parcel, person, bird or an animal. IoT applications of RFID are in business processes, such as parcels tracking and inventory control, sales log-ins and supply-chain management. DEPT. OF ECE, SJBIT 53

54. Bluetooth BR/EDR and Bluetooth Low Energy A device may have provisions for single mode BTLE( bluetooth low energy) or dual mode BT BR/EDR (basic rate and enhanced data rate) (Mbps stands for Million Bits per second). Its features are: Auto-synchronization between mobile and other devices when both use BT. BT network uses features of self-discovery & self-configuration Radio range depending on class of radio; Class 1 or 2 or radios: 100 m, 10 m or 1 m used in device BT implementation. DEPT. OF ECE, SJBIT 54

55. Support to NFC pairing for low latency in pairing the BT devices. Two modes—dual or single mode devices are used for IoT/M2M devices local area network. IPv6 connection option for BT Smart with IPSP (Internet Protocol Support Profile). Smaller packets in LE mode. Operation in secured as well as unsecured modes (devices can opt for both link-level as well as service-level security or just service level or unsecured level). DEPT. OF ECE, SJBIT 55

56. DATA ENRICHMENT, DATA CONSOLIDATION AND DEVICE MANAGEMENT AT IOT/M2M GATEWAY DEPT. OF ECE, SJBIT 56

57. IoT or M2M gateway consisting of data enrichment and consolidation, device management and communication frameworks at the adaptation layer DEPT. OF ECE, SJBIT 57

58. Data Management and Consolidation Gateway Gateway includes the provisions for one or more of the following functions: transcoding and data management. Following are data management and consolidation functions: Transcoding Privacy, security Integration Compaction and fusion DEPT. OF ECE, SJBIT 58

59. Transcoding Transcoding means data adaptation, conversion and change of protocol, format or code using software. The gateway renders the web response and messages in formats and representations required and acceptable at an IoT device. Similarly, the IoT device requests are adapted, converted and changed into required formats acceptable at the server by the transcoding software. DEPT. OF ECE, SJBIT 59

60. Privacy Data such as patient medical data, data for supplying goods in a company from and to different locations, and changes in inventories, may need privacy and protection from conscious or unconscious transfer to untrustworthy destinations using the Internet. Privacy is an aspect of data management and must be remembered while designing an application. The design should ensure privacy by ensuring that the data at the receiving end is considered anonymous from an individual or company. DEPT. OF ECE, SJBIT 60

61. Following are the components of the privacy model: Devices and applications identity-management Authentication Authorization Trust Reputation DEPT. OF ECE, SJBIT 61

62. Secure Data Access Access to data needs to be secure. The design ensures the authentication of a request for data and authorization for accessing a response or service. It may also include auditing of requests and accesses of the responses for accountability in future. DEPT. OF ECE, SJBIT 62

63. Data Gathering and Enrichment IoT/M2M applications involve actions such as data-gathering (acquisition), validation, storage, processing, reminiscence (retention) and analysis. DEPT. OF ECE, SJBIT 63

64. Energy Dissipation in Data Dissemination Energy consumption for data dissemination is an important consideration in many devices in WPANs and in wireless sensor nodes (WSNs). This is due to limited battery life. Energy is consumed when performing computations and transmissions. Higher the data rate, the greater will be the energy consumed. Higher is RF used, the greater will be the energy consumed. Higher the gathering interval, the lower will be the energy consumed. DEPT. OF ECE, SJBIT 64

65. Data Source and Data Destination ID: Each device and each device resource is assigned an ID for specifying the data of source and a separate ID for data destination. Address: Header fields add the destination address (for example, 48-bit MAC address at Link layer, 32-bit IPv4 address at IP network and 128-bit IPv6 address at IPv6 network) and may also add the port (for example, port 80 for HTTP application). DEPT. OF ECE, SJBIT 65

66. Data Characteristics, Formats and Structures Data characteristics can be in terms of temporal data (dependent on the time), spatial data (dependent on location), real-time data (generated continuously and acquired continuously at the same pace), real-world data (from physical world for example, traffic or streetlight, ambient condition), proprietary data (copy right data reserved for distribution to authorized enterprises) and big data (unstructured voluminous data). Structure implies the ways for arranging the data bytes in sequences with size limit DEPT. OF ECE, SJBIT 66

67. WEB COMMUNICATION PROTOCOLS FOR CONNECTED DEVICES Data of connected devices routes over the web in two types of communication environments. The environments are: Constrained RESTful Environment (CoRE): Unconstrained Environment: DEPT. OF ECE, SJBIT 67

68. Constrained RESTful Environment (CoRE): IoT devices or M2M devices communicate between themselves in a Local Area Network. A device typically sends or receives 10s of bytes. The data gathered after enriching and consolidating from a number of devices consists of 100s of bytes. A gateway in the communication framework enables the data of networked devices that communicate over the Internet using the REST software architecture. DEPT. OF ECE, SJBIT 68

69. Unconstrained Environment: Web applications use HTTP and RESTful HTTP for web client and web server communication. A web object consists of 1000s of bytes. Data routes over IP networks for the Internet. Web applications and services use the IP and TCP protocols for Internet network and transport layers DEPT. OF ECE, SJBIT 69

70. DEPT. OF ECE, SJBIT 70

71. Constrained Application Protocol Constrained Application Protocol (CoAP) which is for CoRE using ROLL data network. IETF(Internet Engg Task Force) DEPT. OF ECE, SJBIT 71

72. Features of CoAP are: An IETF defined application-support layer protocol CoAP web-objects communicate using request/response interaction model. A specialized web-transfer protocol which is used for CoRE using ROLL network. It uses object-model for the resources and each object can have single or multiple instances. Each resource can have single or multiple instances. Supports the resource directory and resource-discovery functions DEPT. OF ECE, SJBIT 72

73. (a)Direct and indirect accesses of CoAP client objects to a CoAP server. (b) CoAP client access for lookup of object or resource using a resource directory. (c) CoAP client and server access using proxies. DEPT. OF ECE, SJBIT 73

74. Lightweight Machine-to-Machine Communication Protocol Lightweight Machine-to-Machine Communication (LWM2M) protocol is an application layer protocol specified by Open Mobile Alliance (OMA) for transfer of service data/messages. The protocol enables communication between LWM2M client at IoT device and an LWM2M server at the M2M application and service capability layer. The protocol is a compact one, meaning small header. It has an efficient data model. It is generally used in conjunction with CoAP. DEPT. OF ECE, SJBIT 74

75. DEPT. OF ECE, SJBIT 75

76. LWM2M specifications and features are as follows: An object or resource use CoAP, DTLS (Datagram Transport Layer Security), and UDP or SMS (short message service) protocols for sending a request or response. Use of plain text for a resource. An object or its resource access using an URL(Uniform resource locator) Interface functions are for—bootstrapping; registration, deregister or updating a client and its objects; reporting the notifications with new resource values; and service and management access through the server. Use of object model for resources and each object can have single or multiple instances. DEPT. OF ECE, SJBIT 76

77. JSON Format Features of a JSON are: JSON is an open-standard format used primarily to transmit data between a server and web application, as an alternative to XML. The text is human readable. It transmits data objects as text to transmit. It consists of attribute- value pairs. Originally derived from the JavaScript scripting language, JSON, is now a language-independent data format, the coding of which can be in Java or C or another programming language used for parsing and generating JSON data. DEPT. OF ECE, SJBIT 77

78. MESSAGE COMMUNICATION PROTOCOLS FOR CONNECTED DEVICES Terminology: Request/Response (Client/Server) Publish/Subscribe (pubsub) Resource Directory Resource Discovery Registration/Registration Update Pull (Subscribe/Notify) Data Polling or Observing Push (Publish/Subscribe) Data Message Cache Message Queue Information/Query DEPT. OF ECE, SJBIT 78

79. Communication Protocols COAP-SMS Constrained Application Protocol (CoAP) - Short message service M2M or IoT device uses SMS quite frequently. SMS is identified as the transport protocol for transmission of small data (up to 160 characters). It is used for communicating with a GSM/GPRS mobile device. DEPT. OF ECE, SJBIT 79

80. (a)A CoAP request or response communication to a machine, IoT device or mobile terminal (MT), (b)A computer or machine interface using IP communication to a mobile service provider for data interchange with terminal, (c)A machine or IoT device or mobile origin (MO) communication of CoAP request or response communication, and (d)An origin communication using SS7/CIMD/SMPP with a computer or machine interface using IP communication DEPT. OF ECE, SJBIT 80

81. DEPT. OF ECE, SJBIT 81

82. SMS is used instead of UDP + DTLS by a CoAP client or server. A CoAP client communicates to a mobile terminal (MT) endpoint over the General Packet Radio Service (GPRS), High Speed Packet Access (HSPA) or Long Term Evolution (LTE) networks using CoAP-SMS protocol. DEPT. OF ECE, SJBIT 82

83. The CoAP-SMS features are as follows: An URI used as coap+sms:// in place of coap://. (Uniform resource identifier) A CoAP message encodes with alphabets for SMS communication. An SMS message consists of 160 characters in 7-bit encoding of a character. Maximum length for a CoAP message is thus 140 B (= 160 ? 7 bits/8 bits) CoAP endpoints have to work with a Subscriber Identity Module (SIM) card for SMS in cellular networks. Does not support multi-casting. Two additional options are Response-to-URI-Host (RUH) and Response-to-URI-Port (RUP) Data interchange sequences. Authentication of a client by the server provides the security. MSISDN of the MS and SIM based security is used during SMS data exchanges. DEPT. OF ECE, SJBIT 83

84. COAP-MQ Constrained Application Protocol (CoAP) – message Queue M2M or IoT device uses message queuing quite frequently due to ROLL environment and constrained devices (awake only when initiated) or connection- breaks for long periods. CoAP-MQ is a message queue protocol using a broker and RD. Roles of CoAP endpoints have roles as a client and server. DEPT. OF ECE, SJBIT 84

85. Data interchanges between CoAP-MQ endpoints, CoAP-MQ clients, CoAP-MQ servers through CoAP-MQ broker and its services. DEPT. OF ECE, SJBIT 85

86. MQTT Protocol (Message Queuing Telemetry Transport )(MQTT) It is an open-source protocol for machine-to-machine (M2M)/IoT connectivity. Word 'telemetry', in English dictionary, means measuring and sending values or messages to far off places by radio or other mechanism. DEPT. OF ECE, SJBIT 86

87. Messages interchange between M2M/IoT device objects (publisher and subscriber) and web objects (publisher and subscriber) using an MQTT Broker DEPT. OF ECE, SJBIT 87

88. MQTT Broker (also referred simply as MQ) does the following: Functions as a server node capable of storing messages from publishers and forwarding them to the subscribing clients. Receives topics from the publishers. Examples of topics are measured information of ambient light conditions, traffic density, nearby parking space availability and waste container status. Performs a store-and-forward function, stores topics from publishers and forwards to subscribers. Receives subscriptions from clients on the topics, matches subscriptions and publications in order to route messages to right endpoints. Recovers subscriptions on reconnect after a disconnection, unless the client explicitly disconnected. DEPT. OF ECE, SJBIT 88

89. Acts as a broker between the publisher of the topics and their subscribers. Finds client disconnection until DISCONNET message receives, keeps message alive till explicit disconnection. Retains the last-received message from a publisher for a new connected subscriber on the same topic, when retain field in the header is set. Authentication by Username/Password in connect message and client security is through SSL/TLS. Security considerations are same as of CoAP, web-linking and CoRE resource directory. Support from Intelligent and business analyst server and other servers through a MQTT server with a gateway. DEPT. OF ECE, SJBIT 89

90. XMPP (Extensible Messaging and Presence Protocol) XMPP is an XML-based specification for messaging and presence protocols. XMPP is also an open-source protocol recommended specification which is accepted by IETF. RFC is an international organization and stands for 'Recommended for Comments'. RFC 6120 document specifies the XMPP for CoRE. RFC 6121 XMPP specifies the instant messaging (IM) and presence, and RFC 6122 XMPP specifies the (message) address format. DEPT. OF ECE, SJBIT 90

91. Use of XMPP and XMPP extension protocols for connected devices and web objects for the messaging, presence notifications, responses on demand and service discoveries using XML streams DEPT. OF ECE, SJBIT 91

92. Features of XMPP are: XMPP uses XML. XML elements are sent in the open-ended stream within the tag and corresponding end tag. Three basic types of XMPP stanzas (elements) are: message presence iq (information/query, request/response) Extensibility to constrained environment messaging and presence protocols as well as IP network messaging. Extensibility of request-response (client-server) architecture to iq (information through querying), PubSub messaging, Chat room MUC messaging and other architecture (where group of people exchange information when present in a chat room), decentralised XMPP server. DEPT. OF ECE, SJBIT 92

93. XMPP does the following: Binary data is first encoded using base 64 and then transmitted in-band. Therefore, the file first transmits out-of-band between nodes on messages from XMPP server but not directly like IMs. No end-to-end encryption Higher overhead being text based in place of binary implementations No support for QoS like MQTT does DEPT. OF ECE, SJBIT 93

94. End of module 1 DEPT. OF ECE, SJBIT 94